Too much crosstalk
These tubes exhibit way too much crosstalk between sections for me to use in my Fender amps. Any signal being amplified by the first-stage will be heard in the second-stage output, rendering the volume control of little use below about 2 or 3. Above that setting, the second-stage gain will dominate, but phasing occurs at low settings, and there will still be sound with the volume control entirely off. Other than that, the tone is very nice, but these tubes just won't work in high-gain circuits.